What the fruit fly is for classical genetics and the squid axon for neurobiology, the insect society is for experimental sociobiology. Many of the sociobiological concepts and hypotheses proposed more than 40 years ago were confirmed, modified, revised or advanced by empirical studies with social insects during the past quarter-century.

The remarkable ecological success of social insects, and in particular of ants, is largely based on two key features of insect societies: cooperation and communication. In fact, a central element of any social behaviour is communication (see Chapter 8). The study of communication behaviour is at the core of any attempt to analyse social organisations. Without communication, social interactions and cooperation of any kind are impossible, be they interactions between genes in a genome, between organelles inside a cell, interactions of cells and organs in organisms, or cooperation among individuals in societies.

From early on in my scientific career I was interested in decoding communication mechanisms in social insects, particularly in ants, and I was fascinated by the comparative exploration of the evolutionary origin, function, diversity and complexity of social systems. I was, and continue to be, intrigued by the universal observation that wherever social life in groups evolved on this planet, we encounter (with only a few exceptions) a striking correlation: the more tightly organised within-group cooperation and cohesion, the stronger the between-group discrimination and hostility.